Treatment of Adamantinoma
Complete surgical excision with wide margins is the definitive treatment for adamantinoma, as this rare low-grade malignant bone tumor is not responsive to chemotherapy or radiotherapy. 1
Surgical Approach
Primary Treatment Strategy
Wide resection is the treatment of choice for all adamantinomas, regardless of grade, as incomplete excision leads to high recurrence rates of approximately 30%. 1
Limb-salvage surgery should be performed whenever feasible rather than amputation, with reconstruction using allografts or prosthetic systems. 2, 3
The surgical goal is achieving negative margins, as positive or close margins significantly increase local recurrence risk. 2
Reconstruction Options
Frozen allograft reconstruction is a well-established option following wide resection, with successful bone union and functional outcomes reported in multiple series. 3
Prosthetic reconstruction may be considered, particularly for large defects, though allograft fracture remains a common complication requiring careful patient counseling. 4
Total bone replacement (e.g., total tibia allograft) is technically feasible but carries higher fracture risk and may ultimately require conversion to prosthetic systems. 4
Special Considerations by Subtype
Low-Grade (Osteofibrous Dysplasia-Like) Subtype
This subtype will recur if not completely resected but has lower metastatic potential. 1
Complete excision remains mandatory despite the lower grade. 1
Classic and Other Subtypes
Higher-grade subtypes have metastatic potential in 10-20% of cases, typically to the lungs, and may require consideration of systemic therapy in advanced/metastatic settings. 1
When higher-grade areas are present in the primary tumor, systemic therapy may be required, though evidence is limited. 1
Critical Management Pitfalls
Inadequate Initial Surgery
Curettage or intralesional procedures are inadequate and lead to inevitable local recurrence. 1
Even marginal excision carries unacceptably high recurrence rates compared to wide resection. 5
Misdiagnosis Leading to Inappropriate Treatment
Adamantinoma is frequently misdiagnosed as other bone lesions, leading to inadequate initial treatment (curettage, cementing) that necessitates subsequent wide resection. 5
Histological diagnosis requires expertise, as the epithelial component can be subtle and easily missed. 4, 5
Surveillance Requirements
Follow-Up Protocol
Long-term surveillance extending beyond 15-20 years is mandatory, as late recurrences occurring after 15-20 years are well-documented. 1, 2
Follow-up should include clinical examination and imaging of the primary site plus chest imaging to detect pulmonary metastases. 1
High-Risk Populations Requiring Intensive Monitoring
Male patients have significantly increased risk of local recurrence (P < 0.05) and require more vigilant surveillance. 2
Patients over 20 years of age at diagnosis also demonstrate higher recurrence rates. 2
Any patient with incomplete initial excision requires lifelong monitoring given the 30% recurrence rate. 1
Role of Adjuvant Therapies
Chemotherapy and radiotherapy have no established role in the primary management of adamantinoma, as this tumor is not chemosensitive or radiosensitive. 1
For advanced/metastatic disease not amenable to surgical resection, systemic therapy options are investigational and should be considered only in clinical trial settings. 1